176 



TECHNOLOGY OF BACTERIA. 



Fig. 3. 



a, wine-glass ; b, glass cover 

 (watch-glass) ; c, bell-glass, sup- 

 ported by a square glass plate. 



suring the greatest possible security from contam- 

 ination by atmospheric germs. 

 The culture-flasks employed 

 contain from one to four fluid 

 drachms. " They are made 

 from glass-tubing of three or 

 four tenths inch diameter, and 

 those which the writer has 

 used in his numerous experi- 

 ments have all been home- 

 made. It is easier to make 

 new flasks than to clean old ones, and they are 

 thrown away after being once used. Bellows, op- 

 erated by the foot, and a flame of considerable size 

 gas is preferable will be required by one who 

 proposes to construct these little flasks for himself. 

 After a little practice, they are rapidly made ; but 



as a large number are re- 

 quired, the time and labor 

 expended in their prepara- 

 tion is no slight matter. . . . 

 After blowing a bulb at the 

 extremity of a long glass 

 tube, of the diameter men- 

 tioned, this is provided with 

 a slender neck, drawn out 

 in the flame, and the end of 

 Flg 4 - this is hermetically sealed. 



(See Fig. 5.) Thus one little flask after another 

 is made from the same piece of tubing, until this 

 becomes too short for further use. 



